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Discussion Starter #1
Hi All

2003 E320

Vehicle has a stubborn P0400 code. So far i have replaced the EGR with a new unit. I also removed and thoroughly cleaned the EGR tube from the manifold. I replaced a few broken hoses and cleaned and resealed the passenger side breather. Cleared code, went for a drive and it has come back.

Anything else i should be looking for? I did not clean the drivers side breather cover. Could this be a solution?
 

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Hello:)

Which hoses have you replaced ?

Have you checked the hose that goes to the MAP sensor in front of the engine ?
 

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Discussion Starter #3
Hi i replaced a few in the back. I did replace the MAP sensor hose. What is wierd is prior i was getting a P0171 code for secondary air injection. I found a hose that was missing and replaced. That code went away and the p0400 showed up. I know EGR is good because it is new and tube is thoroughly cleaned. Is there any tubes i might be missing. Does anyone have a diagram of the vaccum system related to this or could it be something else i am overlooking?
 

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The P0171 code is not for secondary air injection specifically. In any case, I would check the hose and its connection between the EGR valve solenoid and the intake. In the attached diagram the EGR valve solenoid is shown as 89.

I assume you replaced the whole assembly (EGR valve solenoid plus the EGR valve itself) with a new one.

One recent poster replaced the EGR valve assembly, but forgot to connect the hose to the intake manifold outlet, and was wondering why the P0400 was persisting :)
 

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Discussion Starter #5
i defintaely hooked the hose back up to the manifold. In your diagram, would the air combination valves cause this code if dirty? The hose between these was broken before i got this code. Once i replaced that hose the code came.
 

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Which hose replacement are you talking about ? the air injection hose (thick) from the air pump (M33), or the vacuum control hose from the switchover valve (Y32) ?

Make sure that the intake to the switchover valve hose is connected, and the check valve works (air passes in one direction) and properly installed (airflow direction).
 

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Discussion Starter #7
The P0171 code is not for secondary air injection specifically. In any case, I would check the hose and its connection between the EGR valve solenoid and the intake. In the attached diagram the EGR valve solenoid is shown as 89.

I assume you replaced the whole assembly (EGR valve solenoid plus the EGR valve itself) with a new one.

One recent poster replaced the EGR valve assembly, but forgot to connect the hose to the intake manifold outlet, and was wondering why the P0400 was persisting :)

Sorry it was p0410 i believe
 

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Discussion Starter #8
The small one from y32. The side that connected to the drivers side was very brittle and when i replaced it the p410 went away and the p0400 showed up
 

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I do not see the connection between the two, as if the hose to the combination valve is broken, the valve will be closed, and no air injection to the driver's side exhaust manifold. Then you get the P0410. But apart from the initial 90 seconds with the cold engine, and during testing periods these valves remain closed.

If you can clear the codes with a scanner, you can clear the P0400, then introduce the original fault by removing the hose from the combi valve, run the car for a while. You will get a P0410 eventually. But will you also get a P0400 ? This will help diagnose the problem. It could just be an interdependency like for the EGR test to be performed, no secondary injection faults should be present ?
 

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Discussion Starter #10
HI Again,

So i replaced all the vacuum lines now for the most part except for the one in the middle. The two behind the MAP sensor were frayed a little so i changed them. I also took off the cover of the drivers side air injection valve and cleaned it out with some spray.

I reset codes. So far i got the OBD to reset everything except CAT and EVAP. I have driven quite a bit. The p0400 has not come back yet, however 2 new codes show up:
stored code p0151 02 sensor low voltage bank 2 sensor 1
pending dtc p0157 02 sensor low voltage bank 2 sensor 2


i know the sensors should be good as they are about 2 years old.

My question now is:

Since the EVAP and CAT have not reset yet do you think i am past the p0400 code? Why would these new codes show up?

Do you know the drive cycle requirements for reset cat and evap. This car is frustrating.

On a side note it drives really nice lol.
 

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Probably something you did when you tried to clean the reed valve inside the injection valve at the driver's side. If the valve does not properly close (normally closed, only opens when the switchover valve applies vacuum to it), you will have exhaust gasses flow towards the air injection pump. This will look like an exhaust leak which may trigger the fault codes you are having.

No point in completing the drive cycle with the O2 codes you have. You need to address them first.

Remove the thick black hose that comes from the pump, at the driver's side combi valve while the engine is idling. You should not have any exhaust leakage from the valve port that the hose was removed. There should be no air injection either from the pump when the engine is warmed up.

I noticed in W211 forum that you have been having the P0151 problem for a long while. Your car is "W211" version being 2003 E320 sedan.
 

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Discussion Starter #12
Hi

I disconnected the big hose from the drivers side (and passengers side). I did not see any exhaust leakage. Any ideas on where to try next?

Thank you by the way!
 

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I would get the emission test results from the scanner to see what tests have passed and what tests have failed.

I would get the fuel trim values (short and long for both sides) from the scanner

I would also monitor the bank 2 (with the fault code) O2 sensor output to see what it is doing (what is the voltage swing, and in what range (low end or high end of the center line (0.5V).

You may have a bad connection for the O2 sensor at the driver's side, maybe some moisture intrusion. Unplug the connector, use some connector cleaner, let it dry and re-plug.
 

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Discussion Starter #14
So far i reset the code and drove around. All obd systems reset except for CAT and EVAP. I drove quite abit on the highway but still not reset. The P0400 has not shown back up yet (i think the new hoses did the trick) and no stored codes. I do have a pending dtc P0151.

I will drive some more tommorrow to hopefully get the EVAP and CAT set. Will the EVAP and CAT reset if there is a pending DTC?
 

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Pending DTC means that the ECU is not sure whether the problem is with the O2 sensor or something else, and needs more data. CAT testing depends on the proper O2 sensor signaling (both front and rear), so till the O2 problem is addressed, CAT test will not run.
 

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How many miles on your w210 ? Hiway or City miles ?

Thx David
 
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2000 E 320 White Wagon
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